JP-2002-39038A shows a direct injection engine that is started without an aid of a starter, which is referred to as a starter-motorless-start. In the starter-motorless-start, a fuel is injected and ignited in a cylinder that is stopped in the power stroke to generate a combustion energy so that a cranking of engine is caused.
In the intake port injection engine, since an intake valve of the cylinder in the power stroke is closed, the fuel cannot be injected into the cylinder. Thus, the starter-motorless-start, which is disclosed in JP-2002-39038A, cannot be applied to the intake port injection engine.
In an engine control system disclosed in JP-62-255558A, the engine is forcibly stopped at a predetermined poison so that a specified cylinder is always stopped in the power stroke in order to conduct the starter-motorless-start in the intake port injection engine. Just before the engine is completely stopped, the fuel is injected in to the specified cylinder, and then the engine is stopped in a state that the air-fuel mixture is kept in the specified cylinder. In next starting time of engine, the air-fuel mixture is ignited to start the engine. This engine has a shutter valve at the intake port of the specified cylinder in order to forcibly stop the engine at the predetermined position. The shutter valve is closed to prevent an introduction of intake air into the specified cylinder, so that the predetermined specified cylinder is always stopped in the power stroke.
Although the intake port injection engine shown in JP-62-255558A can be started without starter, the structure becomes complicated to cause high-cost. Since the engine is always stopped at the same position, the interval of the engine stop position corresponds to an interval of two rotation of the crankshaft (720° C.A). Unless the engine is forcibly stopped beforehand in a condition where a kinetic energy of inertia rotation is still remained, the inertia rotation of the engine may stop the engine before reaching a next stop position. Thus, it is necessary to stop the engine rapidly, which may cause shocks such as uncomfortable vibrations of the engine.